There are various mattress constructions that use materials that, by themselves or due to some material impurities, can cause or aggravate human allergenic reactions and/or can result in other potentially harmful exposures. For example, materials that incorporate polyurethanes, polyvinyl chlorides, polystyrenes, or polycarbonates all contain volatiles and/or water soluble chemicals that are potentially harmful to human health, safety, and the environment.
A mattress cover typically is the outermost layer or combination of layers in the assembled mattress. The mattress cover functions to isolate the mattress from the human body. That is, the mattress cover is primarily used to provide a barrier between the mattress and the person, limiting deterioration of the mattress and above all preventing the passage of irritating substances, bacteria or parasites from the mattress to the person. The mattress typically contains dusty material (deriving from the natural wool or erosion of the foam rubber) which can pass through the surface of the mattress and irritate the skin. Furthermore, as time passes, the surface layers of the mattress are subject to deterioration and/or contamination with bacteria and parasites. Being that a mattress cover can be in close proximity to or in contact with a user's skin, eyes, mouth, and nostrils, it is preferable not to allow any water soluble or volatile material impurity in the mattress cover or in the mattress itself. The reason being that water soluble or volatile material impurities can be adsorbed or absorbed by the skin, mouth, and the eyes, and inhaled into the mucous membranes and the lungs. These impurities are then transported into the human bloodstream and can cause a negative effect on the user's health.
For example, the deteriorated and/or contaminated surface of the mattress cover can cause skin irritation and/or an allergic reaction. More specifically, there is a risk that the movement of air over and through the mattress cover with water soluble or volatile material impurities can transport mattress volatiles to the sensitive lungs of infants, asthmatics, or hyper-allergenic humans.
The typical exposure to a mattress used in bedding and furniture can range from about 6 hours per day for adults to as high as 18 hours or more per day for infants. Due to the typically high amount of exposure to mattress materials, there is a need for non-toxic material construction of mattress covers as well as the mattresses themselves.
The mattress covers produced so far only partly satisfy the above requirements: for example, the barrier effect is obtained by considerably increasing the thickness of the sheet or adding plastic materials. In some cases fabrics impregnated with antibacterial materials have been used but in this case the antibacterial product can be easily released, creating problems of skin toxicity and loss of the barrier effect of the cover. There is therefore a need for mattress cover sheets free from the above limitations which are able, in particular, to provide an effective barrier and at the same lime are biocompatible and comfortable for the user.